Emilia Clarke, who made her debut in the Marvel Cinematic Universe with Secret Invasion, was also offered the role of Anastasia Steele from Fifty Shades of Grey, which later on was done by Dakota Johnson.

Source: https://www.koimoi.com/hollywood-news/when-emilia-clarke-rejected-fifty-shades-of-grey-for-having-too-much-of-ndity-making-place-for-dakota-johnson-said-the-entire-thing-is-about-sx/

Now considered a book series that was ahead of its time — and a precursor to "Fifty Shades of Grey" — Anne Rice's The Sleeping Beauty Trilogy is tinged with BDSM and kink, set in a medieval fantasy world.

Source: https://www.popsugar.com/entertainment/sexiest-romance-novels-47734346